Trichanthera

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Trichanthera

Description

Shrubs or trees with minute cystoliths. Shoots articulated, obtusely quadrangular, robust. Leaves opposite, petiolate; blades, ovate to oblong, subcoriaceous, margin entire to undulate. Inflorescences dense, terminal, many-flowered panicles or corymbs, flowers arranged in triads; bracts small, central flower of each triad ebracteolate and lateral flowers subtended by 2triangular bracteoles at base of calyx; pedicels about as long as bracts. Flowers conspicuous, distally densely pubescent; calyx campanulate, deeply 5-lobed, lobes subequal to equal in size, mostly obtuse apically; corolla campanulate, densely silky or tomentose, lower half of tube cylindric, gradually enlarged upwards, limb regular, 5-lobed, lobes red proximally, yellowish distally, red within, subequal, triangular, contorted in bud; stamens 4, didynamous, inserted in middle of corolla tube, exserted from mouth of corolla, filaments united into pairs at base, anthers 2-thecous, thecae equal in size, parallel, introrsely ciliate in a longitudinal line, obtuse or rounded at both ends, staminodes 0; disk annular; ovary with 3 or 4 ovules in each locule, stigma 2-lobed, upper lobe rudimentary, lower lobe oblong. Capsules estipitate, ellipsoidal, pubescent, retinacula present, septae with attached retinacula remaining attached to inner capsule wall; seeds 4, 2 in each locule, lenticular.

Distribution

C America present, Guianas present, Southern America: Peru (Peru present)
Ranging from C America southward to Peru and Brazil; a genus of 2 species and 1 variety found in moist lowland forests, frequently along streams and swampy areas; in the Guianas 1 species and 1 variety.

Studied:

T. gigantea var. guianensis.

Wood

Growth rings absent.
Vessels diffuse, solitary for 30%, the remainder in radial multiples of 2-3, few clusters, 8 (5-11) per sq. mm, outline elliptic, diameter 150 (120-190) µm. Vessel member length 770 (300-1200) µm. Perforations simple, intervascular pits 5-6 µm, often slits confluent; vessel/ray pitting of two sizes: (1) like the intervessel pitting, and (2) large, longitudinal, both types present in the same cell.
Rays uni- and multiseriate 4-5 per mm. The uniseriates few, composed of upright cells, the multiseriates 3-5 cells wide, the body of procumbent and square cells, margin usually 1-2 cells high, occasionally much higher; sheath cells present in some rays. Width 60-80 µm, height up to 3 mm. More or less translucent cystoliths frequently present.
Parenchyma scarce, restricted to a few vasicentric strands, seldom forming a complete ring. Strands of 2-4 cells.
Ground tissue of thin-walled septate fibres. Diameter 23-40 µm, walls 4.5 µm thick, occasionally gelatinous. Pits simple, numerous in radial walls, less frequently in tangential walls. Length 1500 (900-2000) µm. F/V ratio: 1.97.

Notes

Specimens of Trichanthera are sometimes confused with those of the genus Bravaisia, but can be distinguished from the latter by basally rounded and awnless anther thecae, flowers borne on pedicels 2-11 mm long, and capsule which are pubescent at maturity. The anther thecae in Bravaisia are basally awned with a single, subulate projection, the flowers are sessile or borne on pedicels less than 2 mm long, and the capsules are glabrous at maturity.